With the rapid development of broadband services, interconnection between networks are more and more used to bear more services. A link and a node on the link may be protected by various methods in a network according to the technology applied in the network. With growing demands and increasing requirements for protecting the traffic, some operators also proposes that it is need to protect the network interconnection. The protection here may be implemented through a port aggregation method. A common method may be the port aggregation method and may be also a loop protection method. A standard commonly applied in the link aggregation method at present supports the port aggregation on one node, thus the link aggregation method can be only applied to link protection. It can not to implement the protection required for a node on a network edge interface through the current link aggregation technology.
Therefore, in order to realize the diversification of the networking modes of a network interconnect area between networks, and the protection not only protection for a link, but also for an edge node, it is proposed by the Institute of Electrical and Electronics Engineers (IEEE) standards organization of the United State to extend the link aggregation, so as to realize the network interconnect protection demand with dual redundancy of links and nodes through a distributed LAG, i.e. a Distributed Resilient Network Interconnect (DRNI). That is, a portal of an aggregation group comprises a multiple nodes, and the aggregation links of the multiple nodes form an aggregation link group.
FIG. 1 is a schematic diagram illustrating connections of the network interconnect nodes according to the related art. As shown in FIG. 1, two portals A and B of an LAG are both provided with two nodes. The two nodes of Portal A of the LAG are System 1 and System 2, and the two nodes of Portal B of the LAG are System 3 and System 4. A multiple links of these four systems are aggregated to form an LAG. Dual protection of the links and nodes may be implemented through such a distributed LAG. System 1 and System 2 in Portal A of the LAG communicate through connection of an internal link, while System 3 and System 4 in Portal B of the LAG also communicate through an internal link.
Currently, in the DRNI, it is implemented to protect and share a load by distinguishing message services. However, it can be hardly ensured that the traffic of the same service can be transmitted on the same aggregation link due to that the traffic is distributed by two ends respectively, which is contradictory to the application of that the DRNI is used to protect the network interface and inconsistent with the demand of the Metro Ethernet Forum (MEF) for protecting of the network interface.
At present, there is no effective solution for the problem in the related art that the same service or session cannot be transmitted bi-directionally on the same path.